Materials are produced today using a range of processes ranging from time intensive outdoor growth and harvesting to energy intensive factory centric production. As demand for raw goods and materials rise, the associated cost of such materials rises. This places greater pressure on limited raw materials, such as minerals, ores, and fossil fuels, as well as on typical grown materials, such as trees, plants, and animals. Additionally, the production of many homogenous materials and composites produces significant environmental downsides in the form of pollution, energy consumption, and a long post use lifespan.
Conventional materials such as expanded petroleum based foams are not biodegradable and require significant energy inputs to produce in the form of manufacturing equipment, heat and raw energy. Conventionally grown materials, such as trees, crops, and fibrous plants, require sunlight, fertilizers and large tracts of farmable land.
Finally, all of these production processes have associated waste streams, whether they are agriculturally or synthetically based.
Fungi are some of the fastest growing organisms known, with some types, such as Neospora sp., growing up to 40 μm/minute. Fungi exhibit excellent bioefficiency, of up to 80%, and are adept at converting raw inputs into a range of components and compositions. Fungi are composed primarily of a cell wall that is constantly being extended at the apex of the hyphae. Unlike the cell wall of a plant, which is composed primarily of cellulose, or the structural component of an animal cell, which relies on collagen, the structural oligosaccharides of the cell wall of fungi rely primarily on chitin and Beta Glucan. Chitin is a strong, hard substance, also found in the exoskeletons of arthropods. Chitin is already used within multiple industries as a purified substance. These uses include: water purification, food additives for stabilization, binders in fabrics and adhesives, surgical thread, and medicinal applications.
Given the rapid growth times of fungi, its hard and strong cellular wall, its high level of bioeffeciency, its ability to utilize multiple nutrients and resource sources, and, in the filamentous types, its rapid extension and exploration of a substrate, materials and composites produced through the growth of fungi can be made more efficiently, cost effectively, and faster than through other growth processes and can also be made more efficiently and cost effectively than many synthetic and organic processes.
Numerous patents and scientific procedures exists for the culturing of fungi for food production, and a few patents detail production methods for fungi with the intent of using its cellular structure for something other than food production. For instance U.S. Pat. No. 5,854,056 discloses a process for the production of “fungal pulp”, a raw material that can be used in the production of paper products and textiles.
Accordingly, it is an object of the invention to provide a method for the culturing and fruiting of filamentous fungi specifically for the production of materials and composites composed in part, or entirely of, hyphae and its aggregative form, mycelia and mycelium, when such hyphae are formed into a fruiting body.
It is another object of the invention to provide a material made in part or in whole of cultured fungi.
It is another object of the invention to provide an enclosure for growing composites and materials comprised of fungi fruiting bodies.
It is another object of the invention to provide a mixture of particles for use in the growing of filamentous fungi to produce a homogenous or heterogeneous material.
Briefly, the invention provides a method for producing grown materials and, in particular, provides a method of using the growth of an organism to produce materials and composites.
In accordance with the invention, a fungus is cultured for the production of a material using the vegetative phase of the fungus, mycelium. This fungus is typically a Basidiomycete.
Basidiomycetes are a phylum of fungi that create a fruiting body (mushroom) to produce spores as a method of sexual reproduction. These fruiting bodies are diverse and take specific forms based on environmental, chemical, and physical stimuli from the substrata/environment from which the fungus is grown.
In this disclosure we describe a series of processes that allow fruiting bodies to be rapidly grown into a low density, chitinous material that can replace balsa, bass, other woods, and also many foamed plastics.
Growing a tree requires 7 to 8 years of favorable outdoor environmental conditions, while our fungal material can be grown in as little as 3 weeks from initial substrate inoculation to final product1. The fruiting body, from which the structural material is derived, can be grown to near net shape by encapsulating the fungal primordium in an enclosure of the desired form which controls the microclimate. By growing the fungal fruiting body to a desired shape only minor post processing is required, reducing waste. Controlling the microclimate around the fruiting body allows precise modification of the fruiting bodies morphology including pileus2 to stipe3 length, pileus and stipe shape, diameter, thickness, density, surface finish, fiber orientation, color, length, and width. Additionally, fruiting bodies, either formed using an enclosure or by other means, can be post-processed to desired material dimensions including shapes such as blocks, cylinders, sheets, spheres, and other combinations of three dimensional solids. Manufacturing processes that may be employed during post processing include, but are not limited to, machining, forming, pressing, drying, sanding, cutting, milling, turning, burning, heating, drying, cooling, water jet cutting and drilling. 1 Regarding G. lucidum. Growth of Fruitbody Formation on G. lucidum on Media Supplemented with Vanadium, Selenium, and Germanium. Tham, L; et al. 19982 A pileus is the mushroom cap that contains either spore tubes or gills, pl. plieuses3 A stipe is the mushroom stalk
Although the majority of Basidiomycetes and some macro Ascomycetes are applicable for creating structural materials utilizing fungi tissue, the order of Polyporales was selected particularly for its production of structural spore tubes, pilei, and stipe that exhibit rigid or plastic material properties as well as a excellent strength characteristics at a range of densisites.
The spore tubes located on the pilei form a honeycomb structure that is comprised of individual, hollow columns that form a network of cylinders that is compressible laterally but stiff along the longitudinal axis, this is present in species Fomes fomentarius and Ganoderma appalantum for example. The genus Polyporus has thus far yielded the best pileus and stipe for composing a solid material with no spore tubes or cylindrical voids; these include: P. squamosus, P. avleolaris, Fomes. fomentarius, and I. obliquus. 
Density calculations of solid sections of formed and processed fruiting bodies have yielded a higher density for stipe (stalk) fibers of up to 350 kg/m3, while the pelius (cap) had a mean density of 180 kg/m3. Spore tube densities on formed and processed sections of G. appalantum and F. fomentarius are 390 kg/m3 and 340 kg/m3 respectively. These densities are comparable to the bulk densities of marine balsa wood, which ranges from 80 kg/m3 upwards to 350 kg/m^3, and the densities of synthetic plastic foams.